Experimental Study On Anti-Storm And Anti-current Characteristics Of Square Sea Cage

With the growing demand for seafood and the decline of marine fishery resources (especially the inshore fishery resources), cage culture is developed rapidly. It becomes a new increasing point of the marine fishery. Traditional sea cages were weak against storm and current, and were easily destroyed. Most cages were put in bay and the environment was polluted. The polluted environment influenced the growth of fishes, even caused diseases. Now cages are increasingly located offshore. But at the locations that are more exposed to waves, winds and currents. In the severe condition the cage volume is sharply decreased due to the action of currents. The cage systems are easily destroyed by winds and waves. That will cause a great loss to fish farmers. This calls for new technological challenges to the anti-current and anti-storm capability of sea cages.The model tests were carried out to investigate the mechanical performance of a square cage. The strain of cage frame, the tension of rope and the volume of a cage were measured and analyzed. Based on the experimental results, the conclusions can be got.1. Relationship between deformation of the floating frames of cages and waves.The period of deformation of floating frames is in accordance with the period of wave. The maximum distortion points appear at the front corner of inner floating pipe and the center of inner floating pipe along the direction of wave travel when the face of the square cages is pendicular to the wave direction. At the same wave period or wavelength, passive distortion increases with increase of wave height and negative distortion sometimes monishes in certain periods. At the same wave height, the maximum distortion appears at a certain wave period.2. Relationship between the tension of rope and waves.At a certain period (wave-length), the maximum tension of rope increases...